Two dots over a vowel is normally called a dieresis. There is a special case of the dieresis in German where the two dots cause the vowel to change (sound and meaning): this special case is called umlaut.
When a vowel has two dots over it (diaeresis), it indicates that the vowel is to be pronounced as a separate syllable rather than combined with the previous vowel. This is common in some languages, like German and Dutch, to show that the two vowels should be pronounced individually.
It is known as an umlauts. It is not used in English, but is used over a vowel, especially in German, to indicate a different vowel quality.
Two dots above a vowel typically indicate that the vowel should be pronounced as a separate syllable or with a different sound. This diacritic mark is known as a diaeresis or umlaut, and it is commonly used in various languages such as German and Hungarian.
The dots over i and j are called tittles. This is what wikipedia says:The tittle first appeared in Latin manuscripts in the 11th century, to distinguish the letter i from strokes of nearby letters. Although originally a larger mark, it was reduced to a dot when Roman-style typefaces were introduced.The 'u' or 'j' with two dots over are used in some languages,hungarian, Portuguese, to represent a different vowel sound to the English sound.I think they represent a vowel that is more 'fronted' than the English vowel.
The letter with two dots is called an umlaut and is pronounced by adding a "y" sound before the vowel. For example, "ü" is pronounced like "ue" in German.
The double dot diacritical mark is a dieresis. In German it's an umlaut.
The letter "ö" with two dots on top is called an umlaut. It is used in various languages such as German and Swedish to indicate a different pronunciation of the vowel. It can change the sound of the vowel and distinguish between different words or meanings.
An "o" with two dots on top is called an "o umlaut" and is pronounced like a long "o" sound in English. It is similar to the vowel sound in the English word "bird."
The two dots above an "a" that make a short "o" sound are called a diaeresis or umlaut. It indicates that the vowel should be pronounced separately and not combined with the preceding vowel.
Those dots and dashes are vowel points.
Umlaut is a diacritic mark that consists of two dots ( ¨ ) placed above a vowel in German and other languages. It indicates a specific sound change in the pronunciation of the vowel.